Re: EPA

[Barry.Parks@mailgw.er.doe.gov]

On Wed, 6 Jul 1994 at 17:05:45 -0400 (EDT), 
"Lorna Bullerwell" <ljb1@postoffice.mail.cornell.edu> wrote:

[Preceding material deleted]

> For instance, why is 10 mrem from any isotope the same as
> 3 mrem from any radioiodine, as implied by the NESHAPs regulations?  I
> thought a rem was a rem no matter where it came from.

There were two different rationales for the NESHAPS regulation. 
The 3 mrem limit for iodine was chosen by EPA to address the risk
of _non-fatal_ thyroid cancer, which of course is unique to iodine.  
In contrast, the 10 mrem limit addresses _fatal_ cancers.

For a reference, see the Federal Register, Vol. 54, No. 240 
(Friday, December 15, 1989), on page 51667.  In the first paragraph, it says:

"...EPA believes that limiting emissions with a baseline standard, represented
by a level of 10 mrem/y ede, will therefore protect public health with an
ample margin of safety.  Furthermore, to insure that the risk of nonfatal 
thyroid cancer does not increase, the standard further provides that no more 
than 3 mrem/y ede out of the 10 mrem/y ede can come from any of the isotopes
of iodine."

P.S. I probably shouldn't say this, but I worked at EPA on the NESHAPS
regulation.  And I AM a health physicist.   But I definitely DIDN'T
make policy!

Barry Parks    Internet:  barry.parks@mailgw.er.doe.gov